Whanganui's only acute mental health facility was operating over capacity at points across 2020 with some patients "occasionally" sleeping on mattresses on the floor.
But staff say that is "an unusual circumstance" and Te Awhina still meets the needs of the Whanganui population.
The inpatient acute mental health service is the only one of its kind in the Whanganui District Health Board catchment and is a 12-bed unit.
But at points across 2020, the unit housed up to 19 patients at a time.
According to the figures released to the Chronicle under the Official Information Act, the facility was deemed over capacity on at least 144 days between December 9, 2019 and December 14, 2020.
The facility was over capacity on at least five occasions across every month of the year, and for 29 of the 31 days in January.
Whanganui Hospital's medical director for mental health, Dr Jo Stephen, told the Chronicle the facility was more than adequate but that there was lack of other facilities for less acute patients.
"We have people who have particular needs, and some of them actually need more what we would call sub-acute beds or long-stay and alternatives to acute admission," she said.
"With those alternatives not available to us, we are feeling the pull."
Stephen said it was "unusual" for patients sleeping on floors while the facility is over capacity but did happen "occasionally".
"A person might sleep on the floor but really it's an unusual circumstance. A situation where they may happen, for example, is when a young person is admitted with their whanau and we needed to accommodate everybody. And when you think about people working marae-style, is it that shocking? Probably not, that's kind of like what we would do at home.
"Sometimes we do use floor mattresses, but we'll try to get whatever kind of bed - we can get a bed from another area. We'll do that."
Asked if the facility could adequately meet the needs of Whanganui's population, Stephen said it could.
"We've got lounges and lots of other spaces, so if necessary, we will pop something into those spaces for them because we need to meet the needs of our population.
"If we feel we can't meet those needs in our district but another district could, we've got a grapevine and we'll find out."
Whanganui DHB chief executive Russell Simpson said: "The unit has a history of not ever declining care unless the bed-state is so extreme that the beds are accessed in other rohe (territories) or in the rare cases whānau members are admitted contemporaneously."
In 2018 the Chronicle reported a similar issue with Te Awhina regularly housing close to 20 patients. In August 2018 that number reached 23.
The newly released information also shows a series of violent incidents at the unit.
Between December 2019 and December 2020, there were 51 incidents of violence at the facility, ranging from the use of "threatening language" to the physical assault of staff or other patients.
While most incidents related to violent language and threats, there were 10 recorded assaults against staff members, resulting in injury on three occasions.
Seven incidents were recorded of patient assaults against other patients, while there was one incident of a patient attacking their own mother.
The DHB confirmed that some resulted in criminal convictions. One incident was described as a "serious assault", while other incidents required staff to take leave.
Dr Peter Skilton, Te Awhina's clinical nurse manager, said the figures were a concern, and reducing the numbers was a priority for the unit.
"Violence is always a concern.
"My view is addressing the genesis and the predisposition to that behaviour at the start will see a greater change in its use."
Skilton said that within a mental healthcare environment, there will always be a degree of violence.
"There is an inherent nature to act out when a person is decompensated, and it's how we respond to that. I'm more keen on reduction on seclusion to zero, reduction in restraint to zero than I am on eradication on something I think is inherent."
Speaking to the Chronicle, Health Minister Andrew Little said the issues of capacity at Te Awhina were "never acceptable".
"But we know there have been major issues within our mental health system for some considerable time."
Little said that while the Government is working to address fundamental issues across the mental health system, it does take time.
"There is extra money going into the system, but it will take two or three years for that to show up in terms of a material difference on the front line.
"When it comes to facilities and expanding facilities, that's going to take longer. But there is a job to do to be constantly vigilant to make sure that consumers of mental health services are not being compromised and staff are not being put in unsafe situations."
National Party mental health spokesman Matt Doocey said the Government wasn't acting fast enough.
"It's hugely disappointing because the Government has said they are going to make real change in mental health, and this is another example where they haven't delivered."
Doocey accepted that consecutive governments over many years had played a role in where the sector is today but said the current government needed to fulfil its promises to overhaul the system.
"The Government has a responsibility to make changes that they promised."